experimental/trunk_client_side_validation/core/src/main/java/org/apache/myfaces/extensions/validator/core/proxy/ProxyMappingPhaseListener.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.myfaces.extensions.validator.core.proxy;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.myfaces.extensions.validator.core.WebXmlParameter;
import org.apache.myfaces.extensions.validator.internal.UsageEnum;
import org.apache.myfaces.extensions.validator.internal.UsageInformation;
import org.apache.myfaces.extensions.validator.util.ExtValUtils;

import javax.faces.component.UIComponent;
import javax.faces.component.ValueHolder;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;

/**
 * due to a restriction at the state saving process
 * a proxy gets a super-class which might impl. StateHolder
 * -> saveState: a StateHolder impl. gets handled before Serializable -> callback doesn't get saved
 * -> restoreState: restoreState of the super-class gets called - no callback -> no interceptor gets executed
 * if a framework (such as trinidad) provides caching it's no problem
 * -> use the web.xml context-param to deactivate the mechanism
 *
 * @author Gerhard Petracek
 */
@UsageInformation({UsageEnum.ALTERNATIVE, UsageEnum.INTERNAL})
public class ProxyMappingPhaseListener implements PhaseListener
{
    private boolean isInitialized = false;

    protected final Log logger = LogFactory.getLog(getClass());

    public void afterPhase(PhaseEvent event)
    {
        if (!isInitialized)
        {
            //don't use DEACTIVATE_PROXY_MAPPING here to allow a different concept
            String initParam = WebXmlParameter.DEACTIVATE_RESTORE_PROXY_PHASE_LISTENER;
            String initAdapterParam = WebXmlParameter.USE_ADAPTERS;

            if ((initParam != null && initParam.equalsIgnoreCase("true"))
                || (initAdapterParam != null && initAdapterParam
                .equalsIgnoreCase("true")))
            {
                ExtValUtils.deregisterPhaseListener(this);
            }
            isInitialized = true;
        }

        if (!event.getPhaseId().equals(PhaseId.RENDER_RESPONSE))
        {
            return;
        }

        Integer processedConverterCount = ExtValUtils
            .getProcessedConverterCount();
        //don't change the comparison with 0 - in order to reduce the overhead.
        //if everything works correctly it's not necessary to inspact the full tree
        //it's just due to a ri bug - normally it's performed during ExtValConverter#intercept#getAsString
        if (ExtValUtils.useProxyMapping()
            && (processedConverterCount != null && !processedConverterCount
            .equals(0)))
        {
            storeComponentConverterMappingForProxies(event.getFacesContext(),
                event.getFacesContext().getViewRoot());
        }
    }

    public void beforePhase(PhaseEvent event)
    {
        if (!event.getPhaseId().equals(PhaseId.APPLY_REQUEST_VALUES))
        {
            return;
        }

        ExtValUtils.restoreProxies();
    }

    public PhaseId getPhaseId()
    {
        return PhaseId.ANY_PHASE;
    }

    /**
     * there is a ri bug (at least with jsp's) -> sometimes getAsString of converters aren't called
     * -> there is no mapping -> if it's the case and there are
     * unhandled editable value hoder components within the page
     * -> search all these components and add the equivalent converter to the mapping
     *
     * @param facesContext reference to the current faces context
     * @param uiComponent  reference to the current component
     */
    private void storeComponentConverterMappingForProxies(
        FacesContext facesContext, UIComponent uiComponent)
    {
        //TODO use the following after the impl. of a better multi-window-mode solution
        //if(!uiComponent.isRendered()) {
        //    return;
        //}

        for (UIComponent child : uiComponent.getChildren())
        {
            if (child instanceof ValueHolder)
            {
                Converter converter = ((ValueHolder) child).getConverter();
                if (converter != null
                    && converter.getClass().getName().contains("$$"))
                {
                    ExtValUtils.getOrInitProxyMapping().put(
                        child.getClientId(facesContext), converter);
                }
            }
            storeComponentConverterMappingForProxies(facesContext, child);
        }
    }
}